Pesticide Use, Mode of Action and Ecotoxicology

Course content

The rationale behind the development of pesticides, their use, their effect on humans and the environment and their subsequent regulation is the frame of references of the course. The importance of mode of action of pesticides will be stressed and linked to chemical properties, uptake, translocation, and metabolism in target and non-target organisms. The evolution of pesticide resistance will be addressed by considering how this compromises normal pesticide action. The principles of assessing pesticide selectivity (including between susceptible and evolved resistant populations) will be an integral part of the course. We deal with formulations of pesticides and use of adjuvants to enhance efficacy, either by the manufacture or by the end-user.

We collect and analyse different types of data, with focus on the biological interpretation and dissemination of dose-response models and results. The statistical programming software R is used throughout the course. Various reference models to assess joint action of pesticide mixtures are taught and the implication to their use is validated and side effects are described.

We focus on aquatic and terrestrial ecotoxicology in relation to pesticide loads, intentional and not intentional discharge in the environment and also the ecotoxicological effects of pesticides on populations and communities.

Some consideration is given to new technology that enables more precise pesticide application and to new biotechnological approaches to pest control that can supplement pesticide use.

Risk assessment of the pesticide use is evaluated in relation to ecotoxicology, and the national and international registration systems.

An excursion to key players within pesticide development and regulation such as: FMC-European Innovation Center, the section of Research and Development of the only Danish pesticide producing company ( and/or Department of Food and Safety monitoring pesticide residues in our food and feed is an integral part of the course.

The curriculum encompasses the advantages and disadvantages of pesticide use and teach critical interpretation of data, the knowledge of which is instrumental for those who wish to work with pesticide development, their management and use in industry, agriculture, horticulture, forestry and on public domains, their legislation and registration.


MSc Programme in Agriculture
MSc Programme in Environmental Science

Learning outcome



- Know how chemical and physical properties of pesticides affect uptake, distribution, metabolisation and excretion of pesticides in plants and animals

- Know the site and mode of action of exemplary pesticides representing the most used pesticide groups: herbicides, fungicides, insecticides and growth regulators

- Know the principles of pesticide use in crops and for non-agricultural purposes (pest and vector control) including resistance risks, application technologies, and pesticide effects on both target and non-target organisms

- Recognize different data types (binary and gradual endpoints) and know how to analyze them

- Know how to assess pesticide effects on humans and the environment using experimental data, database values and statistical models, which are all critically evaluated

- Know the rationale behind pesticide development and registration

- Know how to perform experiments testing pesticide efficacy and toxicity on a range of target and non-target organisms.



-Set up experiments to test for the effect of herbicides, fungicides and insecticides on target or non-target organisms

- Experience with the statistical programming software R

- Perform statistical analysis and biological interpretation of dose-response data from bioassays with various organisms and endpoints

- Find and select valid database values for toxicities and use these to assess risk of both individual pesticides and their mixtures

- Be able to predict mixture toxicity effects of pesticide mixtures and test of potential synergistic or antagonistic mixtures

- Assess efficacy/toxicity of herbicides and recognise characteristic symptoms of exemplary modes of action

- Evaluate toxicity data in a regulatory context

- Apply quantitative methods to assess pesticide load, drift and fate in organisms and environment

 - Know how to collect data from both databases on pesticides and from laboratory experiments, use different digital tools, and statistical models to treat the data, and to critically interpret data and their associated uncertainties based on statistics and a weight-of-evidence approach.



- Evaluate pesticide applications to target and non-target organisms in the terrestrial and aquatic environments

- Put various theories and principles of pesticide action into perspective and make sound judgment of impact of pesticides on different environments

- Discuss pesticide use from a scientific stand in view of its controversial issue in the public

- Understand how knowledge of adverse effects on humans and the environment is used in the risk assessment and legislation of pesticides in Europe. 



Lectures will outline the theoretical background for pesticide chemistry and physical properties, their use and effect on target and non-target organisms and the environment. These lectures are supported by practical and theoretical exercises. The practical exercises are in greenhouse and in growth chambers and will address the topics: herbicide application and symptom development over time, assessment of efficacy, species selectivity, systemicity, effect of exposure duration, use of non-lethal endpoints, pesticide uptake, mode of action, recovery and mixture toxicity. The test organisms are terrestrial and aquatic plants, crustaceans, earthworms and pathogenic fungi. Standard OECD and ISO guidelines and other setups will be used. The theoretical exercises will deal with proper statistical analysis of data from the practical exercises by the use of dose-response curves, calculations of spray applications and pesticide load, simple models to assess fate of pesticides in the environment, calculations of uptake and translocation of pesticides in plants, calculations and discussions of environmental impact of pesticides, risk assessment and legislation needs. The excursion will take place in the last part of the course, giving the students and opportunity to discuss pesticide use, use-principles in the EU and practical testing of pesticide efficacy and safety with the industry.

The exact editions will be written on Absalon.

Examples of course literature:

Stephenson G.R. and Solomon K.R, Pesticides and the Environment, CNTC Canadian Network of Toxicology Centres.


Cedergreen, N. 2017, Manual for laboratory and theoretical exercices

Basic knowledge in chemistry, biology, plant physiology and statistics

Academic qualifications equivalent to a BSc degree is recommended.

Continuous feedback during the course of the semester
Feedback by final exam (In addition to the grade)
Peer feedback (Students give each other feedback)

Written and oral feedback is given for all reports on a report-group basis. All reports thereafter have to be re-submitted. Peer-feedback is given on the final presentation, with different groups being assigned to give feedback on the individual presentations. All students are encouraged to ask questions to practical and theoretical exercises during the course and can be expected to receive feedback on their questions and enquiries.

7,5 ECTS
Type of assessment
Oral examination, 20 min
Type of assessment details
Oral examination in reports and curriculum, 20 min. preparation
Exam registration requirements

4 out of 5 exercise reports are submitted and approved

All aids allowed
Marking scale
7-point grading scale
Censorship form
No external censorship
Two internal examinators

If the requirement is not met, the student has to follow the course the following year as the laboratory exercises need to be followed.

Criteria for exam assessment

See description of learning outcome

Single subject courses (day)

  • Category
  • Hours
  • Lectures
  • 20
  • Class Instruction
  • 5
  • Preparation
  • 100
  • Theory exercises
  • 20
  • Practical exercises
  • 40
  • Excursions
  • 10
  • Project work
  • 10
  • Exam
  • 1
  • English
  • 206


Course number
7,5 ECTS
Programme level
Full Degree Master

1 block

Block 3
The number of seats may be reduced in the late registration period
Study Board of Natural Resources, Environment and Animal Science
Contracting department
  • Department of Plant and Environmental Sciences
Contracting faculty
  • Faculty of Science
Course Coordinator
  • Paul Neve   (6-796b776e7f6e4979756e7737747e376d74)

Paul Neve on the agronomic perspectives and Signe Marie Jensen on statistical treatment and interpretation of data

Saved on the 07-08-2023

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